How much cash or extra money estimate would a family of 4 2 children bring aboard. I am trying to keep within a budget. We would like to do 1 shore excursion per port Costa Maya and Cozumel. Oh, forgot we are sailing on the Fantsay out of New Orleans, Sept. 8 '07. Just trying to liine things up so any advice is great.

good advice except don't forget to tell her that it costs 5 BUCKS to use the ATM on board.

In answer to your question Sassy, alot depends to how much booze and soda you plan to consume, how many pictures you plan to buy, and your wise assertion about shore excursions. Drinks are usually about $5, sodas $2, 8X10 photos $20. SDo estimate from there. Also don't forget they will charge you $10 per day per adult for tips. You always have the right to cancel the charges and pay your own tips, but be aware they are going to do that.

I definitely would not take a cash advance on any credit card. Most credit cards will start charging you high interest from the 1st day you take the money. For a family trying to stay within a budget a cash advance would really hurt you in the long run.
Since you have until September I would try putting a little bit away each week for your "cruise kitty" spending money . Also don't forget to allow for your gratuities onboard, and tipping taxi drivers and baggage handlers. Your onboard gratuities, drinks, photos, shore excursions, gift shop purchases, all can be charged to your onboard account. Then pay it off within thirty days to avoid interest with your "cruise kitty". How much you spend on shore excursions will depend on what type of activities your family likes to do. A simple snorkel excursion averages around $50. You can look at different excursions to get an idea of activities and prices here

Very good point Cruise Fanatic, I guess I used the wrong terminology. I've gotten cash from the casino and they add it to my shipboard account, not actually a cash advance from the CC company's perspective.

Of course most of the time it's not really cash I get but chips for blackjack. That can be a very expensive habit as well.

Take half traveler cheques and half cash. You do not need cash on board. Every purchase you make goes on your sail and sign card. You book your shore excursions on your sign and sail card. Most places takes traveler's cheques on shore but just in case, take some cash. Take whatever you feel comfortable with.